Earth boring apparatus



July 7, 1936. Y c. E. REED 2,047,110

EARTH BORING APPARATUS Filed Feb. 17, 1932 5 sheets-sheet 1 July 7,V 1936. c. E. REED 2,047,110

EARTH BORNG APPARATUS Filed Feb. 17, 1932 5 Sheets-Sheet 2 #uwi i am, MQQMMQM 7% 0 l l 7, m, 2 a

` 5 sheets-sheet 4 CZarnceERed, L www@ c. E. REED EARTH BORING APPARATUS Flled Feb 17 1932 July 7,1936.

C. E. REED July 7, 1 936.

EARTH BORING APPARATUS Filed F'eb. 17, 1932 5 Sheets-Sheet 5 f v m I 9 Patented July 7, 1.936

PATENT OFFICE EARTH BORING ArrAnATUs Clarence E. Reed, Wichita, Kans., asslgnor` to Chicago Pneumatic Tool Company, New York, N. Y., a corporation of New Jersey y Application February 1v, 1an, serial No. 593,650

42 claims. (ci. 25a-'11) This invention is illustrated in the accompanying drawings in which Figure 1 is a central vertical sectional view of the rotary bit head with the roller cutter assembly in place therein.

Fig. la is a side view of the bit head with the roller cutter assembly omitted.

Fig. 1b is a vertical section on line lb--Ib of Fig. 1a.

Fig. 1c is av bottom plan view of Fig. 1a.

Fig. 2 is a, bottom plan view of the bit head with the roller cutters removed.

Fig. 3 is a plan View of section in part on line 3--3 of Fig. 1.

Fig. 3a is a vertical' sectional view on line 3a-3a of Fig. 1 looking towards the right.

Fig. 4 is a vertical section taken centrally of Fig, 1 looking towards the left.

Fig. 5 is a sectional view of another form of cutter assembly, adapted to be inserted into or removed from' the bit head as one unit.

Fig. 6 is a sectional plan view on line 6-6 of Fig. 5, this view also showing the bit head in section.

Fig. 7 is a sectional view of another form of cutter assembly, adapted for handling as a unit. Fig. 8 is a sectional plan View on line 8-8 of Fig. '7, this view also showing bit head in section. Fig. 9 is a detail view showing the side flushing fluid conduitv discharging upon the roller cutter.

The rotatable earth boring bit headv I for boring deep wells is provided at its upper end with a shank of ordinary form, screw threaded (not shown) for attachment to the rotary drill stem. On its exterior the head is of exterior cylindrical form down to the point Iz. Through this cylindrical wall and at a quarter turn from the plane of the drawings in Fig. 1, slots or notches le are formed at diametrically opposite points, to receive lugs 2a projecting from the roller cutter carrying block or member, indicated generally at 2. The interior of the bit head has a socket la and below this are spaced flaring end walls providing a recess between ther'n which :dares downwardly. The socket la is of frustoconical shape, as indicated, with .a shoulder at 6. This frusto-conical portion of the flaring recess extends downwardly to the level of the pointsl I .1: and from this point the walls of this cutter receiving recess are at a greater angle to the vertical and these walls at each side of this fiaring recess on their inner faces Id are fiat. The cutter carrying block 2 is formed longer than wide to nt the flaring recess in thev bit head, as just described.

-head about its vertical axis because of the bolt That is to say, the insertable member 2 is provided with an upper hollow frusto-conical part 2b which, when in place in the head, extends from the shoulder 6 against which its upper edge abuts down to the level of the points Im, Fig. 1, 5 and below this level the wall of the insertable roller carrying member iiares downwardly to conformthe are of the walls Id of the bit head, and the end faces 2e of the insertable member are fiat to fit against the flat walls ld. When 10 the member 2 is inserted into the recess or socket at the lower end of the bit head the lugs or projections 2a thereof will pass into the slots le so that the openingsZa: in these lugs will be axially in line with openings or recesses Iy in those wall portions of the bit head which define theslots I e so that by inserting'bolts 3 through these recesses of the head, and the openings of the lugs, the `insertable member' or block will be held in place. The bolts have suitable heads and nuts, and cotter pins 3a may be employed to complete the fastening.

It will be noticed from the side view Fig. 1a that the bit head is of a. greater dimension from end face If to end face. If than it is from side to 25 side Ig-Ig, as in Fig. 1b, which represents a cross section at right angles to the plane of Fig. 1, or, in other words, the bit head is longer than wide. As viewed in Fig. 1a the dimension from end to end of the head is nearly equal to the diameter of the hole to be cut, it being noted from Fig. 1 that the roller cutters project laterally slightly beyond the end faces lf of the bit head, which end faces, as shown in the bottom plan View in Fig. 1c, are formed on arcs struck from the vertical axis of the bit head.

This construction provides spaces of comparatively large cross sectional area between the sides of the bit head and the wall of the hole, and alsobetween the cylindrical body portion of the bit- 40 head and the wall, of the hole for the escape of the flushing fluid, and the cuttings.

The insertable block'or carrier for the roller cutters partakes of the rotary motion of the bit connections above described and the at surfaces ld and 2e of the head and roller carrying block respectively. These flat or non-concentric surfaces transmit the torque from the bit head to the roller cutter carrier.

The head is provided with a central vertical bore Ik for the down flow of flushing fluid.

Packing can be employed at 6a between lthe shoulder 6 and the upper edge of the roller cutter carrier member. This last mentioned memexov ber is hollow at its upper part within the frustoconical portion as at 2q, and this recess communicates with the central bore of the head to receive the flushing fluid therefrom and to direct it as will be described later.

The roller cutters are shown at 4 these being illustrative of any suitable form of cutters, together with any suitable roller bearings 5.

Spacers 8 may be employed between the cutters and between the cutters and the wall of Athe block or carrier 2. 'I'his roller cutter carrier or block may be either a steel casting or a forging. It has the hollow frusto-conical upper part as above described and below this frusta-conical portion the block is solid except for ports 2d for the flushing iiuid and the recesses 4a in which the roller cutters are located. This central solid portion, which is formed integrally with the upper frusto-conical extension, is indicated at 2c.

This central portion, as shown in Fig. 1, extends down along one side of the block or carrier and to one side of the axis of the drill and it supports the inner ends of the spindles l, la, upon which the roller cutters turn, as the bit head rotates about its vertical axis. At each end of the roller carrier block there is a downwardly projecting wall 2e with flat inner and outer faces 'and in these walls the outer ends of the spindle are mounted. In the arrangement shown as an example of my invention there is one roller cutter on the spindle l. This cutsl a zone at the periphery of the bore hole but leaves uncut a considerable area between it and the vertical axis of the drill, whereas upon the spindle 'la there are supported three roller cutters which cut a zone reaching from a point near the vertical axis of the hole to the wall defining said hole.

The spindles are inclined downwardly and inwardly and spindle 'la reaches to a lower level than the spindle 1. Hence the general relations of the planes of cutting are convergent downwardly towards the vertical axis of the drill, it being noted that the innermost cutter of the set on the spindle 1a has its corner in advance of all other Vcutting surfaces and that from this point, which is near the vertical axis of the drill, the cutting planes incline upwardly and outwardly.

Referring to Fig. 2, which shows a bottom plan view of the roller cutter carrier with said cutters removed, it will be seen that there are three ports 2d for the flushing iiuid arranged substantially on the transverse center line of the member, and that there are two additional ports or passages 2f for the flushing uid. These latter passages are formed in bosses 2h or enlargements on the sides of the cutter block or carrier at the narrow part thereof. This block is reduced in width at X at its central region and the upper endsl of said passages 2f lie adjacent said reduced width portion oi the carrier so that these upper ends of the said passages will communicate with the interior of the hollow frusto-conical upper end of the block to receive the flushing fluid therefrom and direct it downwardly and outwardly it being noted that said passages 2f ineline downwardly and outwardly and have their discharge ends located beyond the outer side of the said carrier or block, as shown in Fig. 4. The fluid is carried down past the cutters by these inclined flushing fluid passages and the iiuid thus impinges directly upon the bottom of the hole with an effect as though ejected from a nozzle.

This type bit is for use in earth formations that disintegrate very rapidly and the disintegrated material collects on the bottom of the hole and the larger pieces interfere with the rotation of the cutters but more particularly the accumulation of material lies on the bottom and the cutters must roll upon it and further pulverize it and push and crowd it out of the way as the bit rotates and the interference of this material prevents the cutter teeth contacting all the time with the virgin material of the earth formation at bottom of bore hole, and thus the penetration of the bit is retarded. The construction shown delivers the fluid under pressure down past the body of the roller cutter to impinge on the bottom of the bore hole and wash it clear of dbris for the advancing cutters to roll upon and disintegrate virgin material of the bottom. These two holes 2f are carried so near the absolute bottom of the bore hole that the fluid they deliver is under the mass of dbris to be floated out and they start and continuously push the material up the bore hole to the surface. It will be noted from the drawings how very narrow this assembly is relative to the diameter of the hole, in this case 121A. This extreme flattening of the assembly at the bottom is to provide ample clearance for the very rapid disposal of the dbris and thus facilitate rapid penetration of the earth formations by the bit. In addition to these two iiuid passages 2f there is one 2d immediately over each of the roller cutters to wash the teeth of any accumulated material. It has been found in practice that the high pressure fluid carrying large percentages of abra- 3 sive materials very rapidly cuts away and destroys the so called wash pipes commonly used to protect bit heads and in many of these designs the passages must divert the fluid from a straight line and wherever the fluid is turned it very quickly destroys the part of the assembly contacted. This invention embraces within the cutter assembly all the parts subjected to destructive wear and with each new set of cutters, all parts of the cutter assembly are replaced new and the highest efficiency is at all times maintained. f

The main member 2 of this cutter assembly requires practically no machine work. The cutters are inserted in their recesses with their roller bearings in place, the spindles are then inserted from the outside through them and the assembly is placed in the bit head socket, and bolted in place. The bolts have for their function only the holding of the assembly in the bit head when it is lifted. The flat faces of the sides of the member 2 contacting the flat angle faces Id of the recess in bit head and the frusto-conical top 2b of the member in the' bit socket take all the working and driving thrusts of operation. As the sides of the bit recess la come down over the ends of the spindles, the spindles cannot work out and need not be otherwise fastened. If for any reason, such as in handling by common laborers as spare parts, it is desired to have the assembled parts held together as a unit, the spindles may be spot Welded to the carrier member, as indicated" on the print at y.

The construction described enables the cutter assembly consisting of the carrier block 2 with the cutters mounted therein to be quickly removed and replaced as one body, it being only necessary to manipulate the bolts for this purpose. When the bolts are removed the cutter assembly will be free to drop from the head or lbe removed therefrom and when said assembly is removed then as an alternative to discarding the entire assembly the spindles readily can be removed, thus allowing the roller cutters to drop 5 out of the carrier or block. Access to the end of one of these spindles can be had at the opening 9 in the carrier block so that the spindle can be tapped to loosen it if need be. After this spindle is removed access can be had to the other 10 spindle. One of the roller'cutters, i. e'., that one located at the inner end of the spindle of the right hand group, is of smaller diameter than the others. It is mounted on an eccentric portion 1a: of the spindle so that its lower cutting surface is in the same inclined Vplane with the lower cutting surfaces of the other cutters of this group. The construction is rugged and of simple manufacture.

The flushing fluid not only washes the cut- `ters but also washes the bottom of the hole at points out towards the periphery thereof. The bit head and the cutter carrier block is reduced in width providing ample space for the flow of the flushing fluid, the cutters being of such diameter that their peripheries project out beyond these reduced sides of the head and cutter carrier block. The spindles for the cutters are held in place by the walls of the bit head.

Itl will be observed that the slots at the sides of the bit head which are intended to receive the laterally projecting lugs on the cutter as sembly block or carrier are open at their lower ends so that in thrusting the cutter carrier or block up into the cavity in the bit head the said lugs will enter the said slots and move along the same until the openings in the lugs register-with the recesses or bolt receiving opening of the head.

.The roller cutter 4b may be designated as a lead cutter. 'It is so disposed that it cuts in ad- 40 vance of the other cutters and slightly to one side of 'the vertical laxis of the bit head. The other cutters, distributed at opposite sides of this lead cutter, act upon an annular area adjacent to but located outwardly from the path of the lead cutter.v All ofthe cutters have their axes disposed in the same vertical plane. The cutter at the left of the axis in Fig. 1 is spaced apart from the group of cutters at the right thereof.

One object attained by this invention is` the 5g provision of a cutter setting characterized by an extraordinary speed of earth penetration, involving al simple, rugged means of assembly, in which the destructive wear and tear of the operations are taken by a member easily and cheap- 53 ly replaced as occasion may demand.

When introducing an earth boring apparatus into the bore hole it sometimes happens that the outlet of the flushing fluid conduits `will become clogged with a part of thel earth formation. T'his 60 is liable to happen where the bore hole contains thickmud or sticky material or where a 4solid mass of shale or other earth formation has bridged the hole and the apparatus in passing into the well encounters this mass resulting in some of the material entering the outlet of the flushing fluid under back pressure. In order to prevent this a closure isprovided vandasone e embodiment of this part of the invention, l2li have shown a closure in the form of. a plug I0 of cy- 70 lindrical form adapted to t with sufficient frictional engagement with the wall of the conduit to be maintained against dropping outin handling the apparatus on the derrick or during the time that the apparatus is being introduced into u the well. The frictional contact, however, isV

such that when the pump is in operation and the ilushing duid is forced through the conduit the pressure of this fluid willy dislodge the plug so that thereafter the flushing operation can go on in the ordinary way. The plug is provided 5 with a head or flange Ilia which will limit its introduction into the discharge end of the conduit. The plug is formed of a material which readily may be ground up by the action of the cutters so as to be discharged from the well withm the dbris and the flushingfluid. Rubber, fiber, cork or wood may be used as material for this temporary closure. The automatic dislodging of the closure may be secured in dill'erent ways, as by pump pressure 15 on the fluid; mechanical force derived from rotation of the bit or by an arrangement of the head of the plug so friction drag oi' the mud in the bore hole would drag the plug out of its closing position. 20 Referring to Figs. 5 and 6 the roller cutter spindles are united inte' one piece 1an: made up virtually of spindle portions like 1, 'la and im oi the form rst described, Fig. 1, and a portion 'ly which forms a support or connection between 25 those spindle portions on which the roller cutters are actually mounted. This connecting portion is welded at W. This composite spindle member bridges the space within the cutter carrier which in this form is made up of sections 2y divided 30 from each other on the axial plane 2z. Each of these sections 2y has a socket or opening 2w in which the ends of the spindle member are supported. Thecutter carrier like in the form first de- 35' scribed is provided with laterally extending lugs. These lugs are split andthere is one section thereof on each section of the carrier as at 2m. When the carrier is assembled with the roller cutters and their spindle section, the sections 2m of the 40 lug match each other as to their bolt openings and said sections bear laterally on each other and the bolt secures them together after the cutter unit has been inserted into the recess of the head with the-lugs in the slots, i. e. each cutter carrier sectionhas its complement of flushing fluid passages.

The centralpassage will be made up into complete form when the sections are assembled, one

half of the conduit being formed in each section. This is true also of the ushing fiuidpassages Zia:

corresponding substantially in position and action to the laterally and downwardly flushing fluid conduits 2f of the form first described.

In making the assembly of the cutters, spindles and carrier member the leading cutter section would be placed on the reduced oreccentric portion of the spindle against the thrust shoulder and then the.spindle portions would be welded together at W. The other cutters then can be placed on the portions of the spindle of full diameter, then the sections of the carrier can be placed on the spindle ends and the whole unit as thus assembled can be inserted in the head with its lateral lugs extending through the slots in the sides of the head and then the bolts can be inserted to hold the entire unit in place, it being observed that the unit is insertable and movable as one body, this being true of both forms of the invention.

It is true also of both forms of the invention that the end faces 2e of the cutter carrier are flat and ilt against the flat faces id. at the ends of the recesses in the bit head.

I show in Fig. 5 that the thrust shoulder 1w against which the lead cutter bears laterally is annular so that said cutter gets a bearing against the shoulder all the way round the spindle. 'I'his form of shoulder can be used in the form first described.

In the form shown in Fig. 5 it will be noted that the tool or tools which actually do the work are mounted in the sectional carrier and are renewable by taking the carrier from the head and separating the sections of saidcarrier from each other. The sockets in which the ends of the spindle member bear are not arranged coaxially but their axes are at an angle to each other. The spindle is therefore locked against rotary movement in its bearings and the tools are held in their prescribed position despite the fact that the v spindle is of angular formation. The spindle is representative of any desired form adapted to extend from side of side of the carrier member and carrying thereon the tool or tools to operate against the formation at the lower end of the bore n hole. The spacers at the outer side of the outside cutters would be preferably welded to the spindle so that with the right and left spindle portions welded together at W and the outside spacers welded to the spindles, the roller cutters and their spindles form a unit to be handled as one body, the spindle being integral from end to end, and the roller cutter being mounted permanently thereon so that in renewing the tool the entire spindle with the cutters would be renewed and it would not be lett to the judgment of the.` man in the field as to how many portions of the cutters or spindles would be renewed. All would have to be renewed in this form of the invention.

In Fig. '7 is shown a form of cutter and carrier assembly in which the two sections of the carrier are indicated at 2t and the spindles are indicated at lay. These spindles like in the form above described have their end portions seated in openings in the end sections of the carrier member and these end spindles have mounted thereon the cylindrical roller cutters which have their cutting portions extending slightly beyond the ends of the bit head to cut the clearance and also to operate upon the bottom of the bore hole. These spindles are connected or supported by an intermediate support integral therewith and shown at 9. The cross bridge or spindle member made up of the 'spindles and the connection portion in this form also affords support for a cone shaped cutter indicated at 4c. This is mounted on a spindle 4d with anti-friction rollers between them, as shown in Fig. 7. This spindle 4d isV screw threaded into a portion of the cross bridge or spindle member and this spindle 4d may be held by a plug 4e inserted in an opening formed through the spindle member to lock the spindle 4d in place or spot welding may be resorted to in order to hold the spindle member against unscrewing. The axis of this cone cutter is inclined downwardly and inwardly in respect to the vertical axis of the drill head and the center of its apex is substantially in the plane of the vertical axis of said bit head. Segments shown inl conduits Zfa. These ports may be arranged at opposite sides of the axis of the cutter carrier.

The central portion of the cross piece or spindle member is extended upwardly and has a flat upper face 'le which abuts against the correspond- 5 ing face on the central portion of the carrier sections.

The sectional cutter carrier is held in the bit head in the same manner as before described.

Where features are susceptible of conjoint use although shown in separate forms and figures, they are to be regarded as belonging to those forms in which they may be used.

'Ihe use of ball and roller bearings in roller boring drill cutters has long been known in the art, but in frusto conical roller cutters having a bore in one side only, the roller covering one end of the spindle or bearing, and owing to the necessity of locking the cutter roller on the spindle, the insertion of balls or rollers and the locking of the cutter on the spindle or bearing has presented great practical difficulties. The method used, inserting ball or roller bearing through a hole or gate and afterwards plugging the hole or gate, has invariably left a projection or a. depression in the wall which interfered with the smooth, progressive freedom of roll of the ball or roller bearing, and the destruction of the balls or rollers thus used as bearings and also as lock means to hold the cutter on the spindle, quickly followed. Often the pressure built up against it expelled the plug and the balls or rollers came out, leaving the cutter also in the well.

'I'his invention provides an assembly in which the roller bearings at all times contact only smooth, unbroken surfaces, thus elminating friction and the usual diilculties and enabling the operator to run this type bit very effectively without oil lubrication and its incidental expenses and troubles.v The design of the conical cutter shown in Fig. 7 distributes the rollers and holds or maintains them in effective working position even when the assembly is quite worn, and the rollers have no function in locking the cutters rotatably on the spindle. Balls may be substituted for the rollers, which are preferable.

These bits penetrate soft earth formations very rapidly, requiring efficient flushing and this lnvention provides a novel and effective nozzle jet at the apex of the cone cutter on the bottom of the hole at the center, which not only flushes the surface of the bottom but the stream washes the advancing edges of the cutter teeth as the stream passes across the face of the cutter in reaching the periphery of the bore hole.

In Fig. 9 is shown a modification in which the l nozzles which project from the sides of the carrier instead of discharging the flushing fluid outwardly upon the formation discharge it inwardly against the cone cutter.

I claim:

1. In combination in a rollerbit, a bit head, a lead cutter set to cut at one side of the axis of the bit head, additional side cutters set at opposite sides of said first named cutter and arranged to enlarge the hole by cutting annular paths adjacent to but outwardly from the lead cutter, the axes of all said cutters being disposed in the same vertical plane, and a one piece carrier m'ember for said cutters seated in a socket in said head, the member having two angularly disposed recesses receiving the side cutters therein, one of said recesses being defined by thrust sustaining shoulders at opposite sides of the associated side cutter.

2. A rotary bit for earth boring drills comprising a head longer than wide, and havingga centrally disposed ilushing fluid passage, a cutter carrier removably mounted in a recess in the head, a plurality of rotary cutters disposed in the carrier with their axes` substantially in a plane extending lengthwise of the carriensaid cutters projecting slightly beyond the ends ofthe head for cutting clearance, said cutters leaving comparatively unobstructed spaces opposite the long sides of the head and .between said long sides and the side of the bore hole, and iiushing iluid passages in the carrier located intermediate the ends of the long sides 'of said carrier communicating at their upper ends with the central flushing uid passage and having their lower ends r spaced farther apart thanthelr upper ends and directed to deliver the iiushing fluid directly upon the formationr at the bottom of the bore hole, substantially as described.

3. A roller cutter earth boring apparatus comprising a bit head, having a Haring recess at its lower end, a cutter carrier in sections divided from each other in the transverse axial plane of the bit head, and having its end walls fitting against the Walls of the flaring recess, said carrier having a recess receiving cutting means, a spindle extending from one separable end wall of the carrier to the other separable end wall thereof across the said recess and seated removably in said end walls, cutter means mounted on said spindle, and means for holding the cutter carrier in the recess of the bit head, substantially as described.

4. Apparatus according to claim 3 in which the spindle is in one piece.

u 5. In apparatus of the class described, having a bit head, a sectional cutter carrier adapted to be inserted into the bit head, a spindle member removably mounted in the separable sides of the carrier, a conical roller cutter mounted on said member at the intermediate portion thereof, other cutters mounted on said member at opposite sides of said conical cutter and means for holding the said carrier in the bit head, substantially as described.

6. Apparatus according to claim 5 in which the cutters at the opposite side of the conical cutter are of cylindrical form, the said conical cutter serving as a lead cutter in respect to the side cutters and arranged with its axis inclining downwardly and inwardly towards the vertical axis of the carrier, said conical cutter being located mainly to cut to one side of said axis close to one of the sidecutters and spaced apart from the other side cutters, substantially as described.

7. In apparatus of the `class described, having a bit head, a cutter carrier having a conical cutter mounted therein and adapted to be inserted into the bit head, said carrier having ushing fluid nozzles directed laterally therefrom at the sides thereof to direct flushing fluid upon the bottom of the hole and conduits for iiushing iiuid and directed to the radial grooves of said cutter to clear the same, substantially as described:

8. A .roller bit cutter assembly comprising a centrally disposed frusto conical cutter positioned in a `carrier for ,cutting at one side only of the bit axis and side cutters enlarging the hole by cutting on bottom, the axes of all cutters in the same vertical plane and the included angle of the frusto conical cutter greater than a, right angle.

` 9. A roller bit cutter assembly for handling as a unit comprising acarrier, side spindles and supporting means therefor jointly extending from end to end of the carrier and having the side spindles seated in bearings in said carrier,

i an inclined spindle intermediate the side spindles, roller cutter means mounted on said intermediate spindle to cut at one side only of the axis of the bit in non-tracking relationship, said side spindles being inclined to the bit axis, the said side spindles yhaving roller cutters dening annular paths outwardlyv from the center cutter means, all cutter axes being in the same vertical plane and the cutters jointly contacting the entire area of bottom of hole.

10. Apparatus according to claim 9, the intermediate spindle portion having a flushing uid conduit. 4

11. A roller cutter organization, for attachment to the bit head of an earth boring apparatus comprising a carrier with means for detachably securing it to the bit head, supporting means for roller cutters removably mounted in thecarrier and including spindles on which the roller cutters turn, a group of said roller cutters being arranged to cut the bottom of the bore hole from the vertical axis of the bit head outwardly towards the periphery of the bore hole and another of said cutters located at theI opposite end of the carrier from where the group oi cutters is located and mounted on one of the said spindles, all of the cutters having their axes in the samr.- vertical plane and cutting the entire area at the bottom of the hole, the said spindles having their ends seated in the walls of the removable carrier, substantially as described.

12. A roller cutter organization according to claim 11 in which the spindles are angularly disposed to each other, said supporting means having a recess in its lower face and a substantially centrally disposed cutting element mounted in the recess and between the side cutting elements of those cutters rst mentioned.

13. A roller cutter earth boring bit head longer than wide, having a recess in its lower end with opposing end walls, the inner faces of which are substantially iiat and incline downwardly and outwardly with respect to the vertical axis of the said head, a socket in the head above and in communication with said recess, the side walls of said socket at points a quarter turn from the end faces of the recess having vertical slots extending therethrough and open at their lower ends, in combination with a roller cutter organization comprising carrier means having a portion to iit into the recess and bearing against the inclined end faces thereof and a portion to iit into the socket with projections extending from the latter portion through the slots and means on the outer side of the bit head for engaging said projection to hold the assembly to the bit head. Y

14. A roller cutter carrier member for earth boring drills adapted for insertion .into the recessed lower end of the bit head of such drills, said member comprising a body longer than wide having end walls aring downwardly and outwardly with bearing openings therein near their lower ends, the axes of said openings being at right angles to the respective flaring wall in which each is formed and said axes being in the same vertical plane, said body having at its upper end a circular portion to flt into a socket in the bit head, a ushing fluid directing passage or passages associated with said circular end portion, said body having a recess between its end walls for roller cutters, said recess opening laterally 9.5 described.

15. A roller cutter organization for earth boring drills comprising roller cutters, spindles on which said cutters are mounted, said spindles having their axesin the same vertical plane, a carrier member for said spindles and cutters, said carrier member having a portion extending downwardly between the roller cutters and having a ilushing fluid passage the outlet of which is directed to one side of said cutter organization and at a point intermediate the length thereof, said carrier having lugs extending laterally from said organization and adapted to be seated in recesses in a bit head, substantially as described.

16. A roller'cutter carrier member for attachment to the bit head of an earth boring apparatus having an upper portion to fit into a socket of the said bit head with lugs on said carrier for securing it to said bit head said carrier having also recesses to receive roller cutters and bearings for theirspindles, and uid passage ways, substantially as described.

17. An earth boring bit comprising a bit head having a recess in its lower end, a roller cutter carrying member fitting said recess and having two roller cutter receiving recesses therein, which converge upwardly, and open laterally and downwardly bearings in said member disposed radially-with respect to the vertical axis of the bit head and axially at a downward and inward inclination to said vertical axis, said bearings being located in the side walls of the carrier, spindles extending across the recesses seated in said bearings, and inclined to the axis of the bit head and roller cutters on said spindles said carrying member having iiushing fluid passages directed upon the cutters and other flushing iluid passages to one side of the vertical plane in which' the axes of the spindles lie for directing fluid past the cutters to impinge upon the bottom of the hole, substantially as described.

18. A cutter unit for a roller boring drill comprising, a cutter carrier member, removable spindles, a cylindrical cutter group mounted on a spindle for cutting from the bit axis to the periphery of the bore hole, another cutter spaced apart and at the opposite side of the unit, the axes of all cutters being in the same vertical plane and cutting the entire 'area of the bore hole, the spindles and a plurality of ushing fluid outlets being within the carrier member within which the cutters are assembled for handling as one body in inserting into or removal from the drill, only the cutters adjacent the periphery of the bore hole tracking each other.

19. In an earth boring apparatus, a drill bit head having a recess in its lower end with a wall inclined relative to the vertical axis of said head, said wall taking end thrusts of a roller cutter organization, a socket in said head and a slot in the side of said head opening into said socket, said slot being open at its lower end, and a recess in the side of the head adjacent the slot.

20. An kearth boring .apparatus according to claim 19 in which the wall of the bit head between the said recess and said slot is perforated to receive a bolt inserted from said recess to hold the roller cutter organization in place in said slot.

21. A roller cutter boring drill having three spindles mounting roller cutters, eachspindle angularly disposed relative to the others, the central spindle having its axis inclined to the drill axis at a different angle than the side spindles, the axes of al1 said spindles being in the same.

vertical plane, a carrier member, the side spindles received in sockets in said carrier member, said carrier member having lugs for attachment to the drill.

22. A composite removable spindle and supporting means for the roller cutters of an earth boring drill having spindlesprojecting from the outer sides of the supporting means, said spindle axes inclining downwardly and inwardly towards the drill axis, and a centrally disposed spindle on said means having its axis disposed at an angle to each of the other spindle axes and inclined in a vertical plane. f

23. A roller cutter boring drill having spindle portions mounting roller cutters, the side spindles inclined relative to the axis of the drill, and being radial thereto, and a central spindle portion having its axis offset in respect to the axis of the side spindles, but in the same vertical plane as the axis of one of the side cutters, a carrier member, the side spindles received in sockets in said carrier member, said carrier member having lugs for attachment to the drill.

24.` In an earth boring drill, roller cutter means contacting the bottom of the bore hole from substantially the axis of the drill to the side of the bore hole, said means cutting clearance for the drill head, said means being mounted on an inclined spindle supported at each end, and additional cutter means cutting on the bottom at the side of the bore hole spaced apart from said roller cutter means and arranged to track the side cutting portion of the first cutter means.

25. In an earth boring drill, a head, roller cutter means contacting the bottom of bore hole from substantially the axis of the drill to the side of the bore hole, said means being mounted on an inclined spindle, the innerportion of which is offset and has its axis parallel with the axis of the outer portion of said spindle, said spindle being supported at each end, and additional cutter means cutting on the bottom at the side of the bore hole spaced apart from said roller cutter means, the side cutter means tracking with the side cutter portion of the roller cutter means first mentioned.

26. A roller cutter organization for earth boring drills comprising a plurality of independent revoluble cylindrical peripheral toothed cutters of different diameters arranged side by side, one of the cutters being a side cutter and the others being center cutters, one of the center cutters having its axis offset and parallel with the axis of the other cutters, the larger diameter center cutter being for cutting an annular area of the bottom of the hole outwardly and upwardly from the center zone thereof, the toothed periphery oi' the smaller of said center cutters cutting at substantially the same radial distance from the axis of the larger cutter as the toothed periphery of the larger cutter.

27. A roller cutter unit for earth boring drills having a central body portion with faces inclined upwardly toward the`axis of the unit, spindles projecting outwardly from said inclined faces with their axes in the same vertical plane mounting cutters that contact the entire area of bottom of `bore hole and a lug projecting laterally from the upper portion of the unit in a plane transverse to the vertical plane of the axes of the spindles for attachment to the side of a drill head at the exterior thereof above the cutters. A

28. A cutter carrier adapted to ilt the head'of an earth boring drill having a recess with sockets in its inner` walls forrolier cutter supporting spindies in lined in upward and outward directions, and ha ing an upper portion with a projection extending laterally from said portion and adapted to project into the side wall oi' the bit head above the cutters for securing the carrier at the exterior of the drill head.

29. A roller bit cutter assembly comprising 'a carrier member and a centrally disposed frustoconical cutter positioned in said carrier member for cutting at one side only of the bit axis and inclined side cutters enlarging the hole by cutting on bottom, the axis of said frusto-conicai cutter being at a diiierent angle to the vertical thanA the angle of side cutter axis.

30. A carrier member in roller earth boring apparatus in which member a spindle is positioned in a recess for a frusto-conical cutter for cutting on bottom at one side only of thel axis of the apparatus, and inclined spindles extending outwardly and upwardly for mounting side cutters enlarging the hole by cutting on bottom, the axis of said spindle for the conical cutter being at a different, angle to the vertical than the axes of said inclined spindles to the vertical.

31. A roller boring drill having approximately cylindrical side cuttingmeans mounted on axes inclined'downwardly and inwardlytowards the longitudinal axis of the drill, and an independent frusto-conical cutting means having rows of cutting teeth and having the apex of the frustrum across the axis of the drill from the cutting means, the axis of the side cutting means and the axis of the frusto-conical cutting means being at different angles to the vertical.

32. An earth boring bit having a bit head with a socket and walls flaring downwardly and outwardly from said socket, a slot opening through the wall of the head into said socket, the inner faces of said flaring walls being in non-concentric relation to the vertical axis of the bit head and the socket therein and a roller cutter carrier having its upper part of form to ilt said socket in the head and having its lower part formed to t the space between said aring walls and to bear on said non-concentric faces to receive the torque, said carrier having a portion tting in said slot which is open at its lower end to receive said portion, and means for retaining the carrier in the socket and slot of the head, substantially as described.

33. A roller bit cutter organization consisting of a carrier mounting a centrally disposed frustoconical cutter, the included angle of which is greater than a right angle, a side cutter at each side of the central cutter, spindles on which the cutters are mounted and supporting means for the spindles, all axes in the same vertical plane.

34. A roller cutter organization for earth boring drills comprising a plurality of independent revoluble cylindrical peripheral toothed cutters of different diameters arranged side by side with their axes in the same vertical plane, the larger of said cutters being for cutting an area of the bottom of the hole adjacent the side thereof, the toothed periphery of the smallerof said cutters operating at substantially the same radial distance from the axis of the side cutter as the lower toothed periphery of the side cutter.

35. In a miler boring drill comprising a one piece roller cutterenclosing one free end of a spindle, a spindle support having integral therewith and at right angles to a. i'ace thereon a projecting annular ange forming the base portion 'bearings positioned between said central cutting of said spindle, a-terminal free end section oi' said spindle having interfitting connection with said ilange, rolling bearings between said cutter and the spindle, positioned in a recess shielding the ends of said rolling bearings from all end l thrust compression between the cutter and the spindle, and floating locking means positioned in a groove partly in said cutter and partly in said spindle and retaining the cutter rotatively on the spindle.

36. In a roller boring drill comprising a one piece roller cutter enclosing the free end of a spindle, the other end of said spindle being integral with the spindle support, and a support,

roller bearings positioned between the cutter and y spindle, said roller bearings shielded in a recess from compression endwise between the cutter and the spindle and annular `frictional bearing surfaces in the cutter bore complementary to frictional bearing surfaces on the spindle, and iioating' means rotatively locking said cutter on said spindle.

37. An approximately i'rusto-conical one piece roller cutter for an earth boring drill having a bore, with a wall portion adapted to frictionally bear on a spindle adjacent the base face oi' the cutter, said bore having a plurality of raceways therein adapted rotatively to receive rolling bearings and shield the ends thereof from compressive thrusts and also receive oating locking means for retaining the cutter rotatively on a spindle, and said cutter bore having another annular surface adapted for sustaining frictional bearing on a spindle portion.

38. In a roller boringv drill and in combination, a plurality of side cutting means tracking each other over an annular area extending inwardly from the side oi the bore hole, which area is inclined downwardly, spindles and roller bearings having axes parallel to said spindles, central Truste-conical cutting means having spaced circumi'erential rows of teeth thereon, the axis of said frusto-conical cutting means being inclined downwardly and inwardly of the drill at a difierent angle than the axis of the side cutting means, roller bearings positioned between said frustoconical cutting means and a spindle, the axes of said roller bearings being inclined to the axis of said spindle in planes converging inwardly oi' the drill.

39. In a roller boring drill and in combination, a plurality of side cutting means tracking each other over an annular area extending inwardly from the side of the bore hole, which area is inclined downwardly, spindles and roller bearings having axes parallel to said spindles, central cutting means having spaced circumferential rows oi' teeth thereon positioned in planes at a dierent angle than the side cutting means, roller means and a spindle, the axes of said roller bearings being inclined to the axis of said spindle in planes converging inwardly of the drill. f

40. In a roller boring drill and in combination, a plurality of side cutters tracking each other over an annular area extending inwardly and downwardly from the side of the bore hole, spindles and roller bearings for said cutters, said bearings having 'axes parallel to said spindles, and cutting means in one piece traversing the area within said annular area and having spaced circumferential rows of teeth thereon, the edges of which teeth denne a cone frustum, roller bearings positioned between said cutting means and a spindle therefor, said roller bearings sustaining radial loads and end thrusts oi said cutting means outwardly' from the axis of rotation oi the drill through contact of the roller peripheries with the cutting means and with the said spindle periphery.

41. A frusto conical roller cutter assembly comprising a roller cutter having an annular frictional bearing surface directly engaging an annular spindle portion, a removable spindle free end portion having a stem within the annular spindle portion, a. floating retainer element oi' rectangular shape in cross section positioned between' the annular and the removable spindle portions, said retainer element bearing on the annular portion and projecting beyond the spindle into a groove formed in the cutter. roller bearings positioned betweenthe removable portion of the spindle and the cutter, and said cutter having an annular bearing surface contacting said removable spindle portion.

42. An approximately frusto-conical roller cutter assembly comprising a roller cutter having an annular frictional bearing surface directly engaging a surface on a spindle, said spindle having a free end separately formed and the other end of said spindle being integral with its support. iloating retaining elements between the cutter and the spindle, said elements bearing on the spindle portion integral with its support and pro- Jecting beyond the spindle into a groove formed in the cutter, and roller bearings positioned between the spindle and the cutter.

CLARENCE E. REED. 

